The main parameters of the drawing of the truss system for the hip roof. Hip roof truss system: specifics of the device and description of the installation process Show the layout of the hip roof truss system

This version of the roof has four slopes. Two of its long inclined surfaces are trapezoidal in shape, and the other two, smaller ones, are in the shape of a triangle - they are called hips. They are located along the gables of the building and connect the ridge with the cornice. Trapezoidal planes have a large area and a slope, also located from the upper horizontal edge to the eaves.

The hip roof has several different designs:

1. Traditional with two trapezoid-shaped slopes and two hips, it is called the "Dutch" roof.
2. Tent - has the same size slopes of a triangular shape. Ideal for square buildings.
3. Semi-hip - hips cover only the upper part of the butt no more than to the middle. Suitable for the construction of houses with an attic, it is called the "Scandinavian" roof.
4. Half-hip - the hips do not have a triangular shape, but are the shape of small trapeziums. Such a roof gives a large attic room, it is also called the "Danish" roof.

Like any other type, the hip type of roof has a frame and a truss system - the whole structure rests on them.

The device of the truss system

The rafter system is the main component of the entire roof structure.

Unlike a gable roof, the device for the supporting structure of a hip-type roof is more complex.

Regardless of whether the building is rectangular or square, the shape of the slopes will not change.

Considering the device of the hip roof rafter system, it can be determined that it consists of several elements:

1. Mauerlat - the basis for the rafters, the link between the bearing walls and the truss system.
2. Skew or diagonal supports - have the greatest length and carry the greatest load.
3. Central rafters - serve to connect the ridge with the Mauerlat on the sides of the slopes, converge at the corners of the ridge from 3 sides.
4. Intermediate rafters - connect the ridge and the eaves.
5. Struts - create not only rigidity, but also provide confrontation with wind loads from the side of the gables of the building, located at different angles to the rafter legs.
6. Narozhniki - the shortest rafters.
7. Sprengel or sprengel trusses - enhance the bearing capacity of the roof structure. They are a beam of timber, located at the corner of the connecting external walls.
8. Racks - give the legs of the supports additional stability, they are installed at the junction of two rafters and a ridge beam.
9. Corner rafter (rib) - located at a smaller angle than the intermediate elements of the system.
10. Short rafter legs - fixed on the corner support board.
11. Skate.
12. Tightening - performs the function of a floor beam.
13. Wind beam - mounted with an inclination on the windy side of the roof.
14. Runs - the distance between the connection of the supports to the ridge.

Installation of rafters

After the type of roof is determined, all the necessary building materials are purchased, you can directly proceed to the construction of the frame.

Before starting the construction of the supporting structure, it is necessary to draw up its project and drawing.

So, the device of the support system consists of several stages:

1. Before starting construction, a wooden beam should be laid around the perimeter of the outer wall - Mauerlat. For its laying, it is necessary to equip a reinforced belt made of reinforced concrete structures that enhance the bearing capacity of the walls. It should be noted that the Mauerlat is securely fixed, preventing the slightest displacement.
2. If the walls are made of stone or brick, a formwork is erected on top of them, into which the reinforcement frame is mounted using galvanized threaded studs, with a caliber of at least 10 mm. The upper part of the studs should protrude 4-5 cm from the base for the supports (Mauerlat).
3. After the frame is installed, the cement mortar is poured.
4. Then, as the concrete hardens, its surface is covered with bitumen and covered with a layer of roofing material or other waterproofing materials.
5. Bars with drilled holes are put on the protruding part of the studs. Fix the structure with nuts.
6. Mauerlat is made from a wooden bar of needles 10 * 15 or 15 * 15 cm dried and impregnated with anti-corrosion and anti-flammable agents. The moisture content of the tree should not exceed 20%.
7. The next step is to install the central beam on the Mauerlat, which is parallel to the ridge. Racks are attached to it. These racks serve as support for a specific part of the support system.

Starting work, it is necessary to check and double-check everything in stages. This is the only way to protect yourself from mistakes and ultimately achieve the most durable design.

Types of hip roof rafters

Hip-type roof supports are divided into two types:

1. Hanging - the beams are located on the beam of the ceiling of the two external walls without additional support.
2. Layered - along the upper edge of the inner walls there is a horizontal beam, to which vertical supports are attached. The basis for the end part of the timber are the outer walls.

The layered type of supports is suitable for buildings with an intermediate supporting wall or columns.

This supporting structure has more base points, so it can be made much easier.

If the building has two load-bearing walls, a screed is installed to support the rafter legs and distribute the load across all vertical supports.

For a hip type of roof, a layered system is considered the most suitable, which gives greater strength and facilitates the construction of the roof.

This modification is used in the construction of an attic or mansard roof.

How to calculate the hip roof rafter system

The calculation of the supporting structure is the main stage in the design of the roof. The slightest miscalculation in the calculations can cause deformation or destruction of the roof.

After studying the roof structure, it is necessary to calculate the angle of inclination of the rafter system. The higher it is, the more the roof is exposed to winds, but it is cleared of snow and ice on its own.

The angle of inclination of the slopes can be 5-60 degrees, it depends on the load of wind and snow.

After determining the angle of inclination, calculations should begin to determine the main loads to which the roof is subject. These include the weight of the roof itself and natural phenomena - wind and precipitation.

The total value of the weight of the supporting structure, lathing, coating and insulation is divided by the area of ​​​​all inclined planes. The resulting value shows the load per 1 m2 of the roof. For a residential building, it must withstand a load of 45-50 kg / m2. This figure is the same for any area.

Sedimentary loads vary depending on the area and amount to 80-150 kg/m2. This value can be found using the "Building Norms and Rules".

The load value must be multiplied by the correction factor:

1. By 1.0 when the tilt angle does not exceed 25 degrees;
2. By 0.7 if the angle value is 25-60 degrees.

If the roof is subject to regular heavy snowfalls, the installation of double supports or continuous battens is recommended.

The determination of the wind load involves the use of the wind pressure coefficient.

The load indicator (wind and snow) is multiplied by an index equal to the value of the rafter pitch. The pitch of the rafters is determined in meters.

The final stage is the calculation of the quantity and criteria of materials.

After calculating all the loads per 1 m2 and on the area of ​​​​the entire roof, the cross section of the supports is determined (the smallest values):

1. Mauerlat - 10 * 10 cm.
2. Puffs and runs - 5 * 15 cm.
3. Filly, struts, crossbars - 10 * 10, 15 * 15 cm.

The number of beams on which the crate is attached and additional elements is calculated by the length of the roof. For example, the length of the roof is 12 m, the step between the rafters is 1 m. Based on this, you will need 24 building legs, 12 on each side.

When carrying out calculations for large-scale projects, it is recommended to use special computer programs for design.

All obtained indicators must be applied to the drawing.

Knots

Accurately calculated knots make it possible to achieve strength and an attractive appearance of the roof.

The connection of elements of roof structures is made according to certain requirements.

The main nodes of the supporting structure:

• ridge knot - a pair of supports is fastened with nails or bolts, and reinforced with bolted beams;
• beam support unit on the Mauerlat - reinforced with metal corners, building brackets, nails or bolts;
• the rafter connection node with a puff, which is located in the middle of the rafter - is carried out using nails or bolts;
• the combination of the brace, rack and support is carried out using die-cutting and reinforced with building brackets.

truss system

The quality of the roof directly depends on the frame and the basis for the roofing. The supporting structure of the roof serves as the foundation and determines its service life.

Rafter system of the mansard hip roof

This support system is resistant to strong wind loads due to the absence of a roof facade wall.

The roof of this form makes it possible to build large plumb lines that protect the walls and foundation of the house from rain, snow and ice.

The constituent elements of the mansard roof rafter system:

1. Mauerlat.
2. Skate and side runs.
3. Support beams.
4. Overhead and hanging rafters.
5. Struts.
6. Support racks.
7. Diagonal rafters.

A distinctive feature of the mansard hip roof is the use of layered and hanging rafters in its design. The upper slope is made from hanging rafters, based on racks or side girder.

To avoid bending, they are equipped with puffs. When installing the lower slope, layered rafters are used with a base on the Mauerlat, and a horizontal beam connecting the rafter system in its middle part.

The lower sloping surfaces have an angle of inclination of about 60 degrees, and the upper ones - at least 30 degrees.

Strengthening the truss system

To ensure the strength and durability of the hip roof, it is not enough to make a truss system, it must also be strengthened.

The most common amplification methods are:

1. Installation of truss bars on the corners of the roof with a stand supporting the diagonal support. If the truss is located far from the corner, it is best to attach a truss truss to it.
2. Installation of racks connected from above with a bar to the ceiling (reinforced concrete) or tightening. They perform the functions of props and ensure an even distribution of the load on the house.
3. The use of double beams instead of a single beam with an excessive length of diagonal rafters.
4. The use of wooden boards 40 * 40 or 50 * 50 mm for the construction of the crate.

A four-pitched roof is familiar to most developers. But its second name - hip can bewilder even an experienced builder. It's all about the triangular end slopes (hips), which replaced the vertical gables.

Why did the creators of such a roof need to complicate the construction of a gable roof, you ask?

There are several reasons for this:

• The aerodynamics of a hip roof is better than that of a gable roof. Therefore, it steadfastly resists strong winds.
• Triangular slopes make the roof rigid and reliable.
• The hip design makes it possible to install wide cornice overhangs along the perimeter of the building, protecting the facade of the building from rain.
• The aesthetic appearance of such a roof is better than a gable roof.

The device and varieties of hip roofs

In order to understand how a hip hipped roof is arranged, consider its main elements.

The design of the hip impassable roof

As can be seen from the diagram, the main elements of this roof are the same as those of a gable roof. There is a ridge run, rafters and mauerlat for attaching them to the wall, racks that support the ridge and struts that unload the middle part of the rafter legs.

The wind beam holds the rafters together during the installation of the roof, and the filly lengthens them, forming roof overhangs. Differences begin with diagonal rafters forming hip slopes. Short rafter legs adjacent to the diagonal rafters are called rafters. To reduce the deflection of long hip beams, sprengels are placed under them. This is the name of short T-shaped racks-stands, cut into the Mauerlat with their ends.

Depending on the width of the building and the presence of internal walls on hip roofs, two types of truss structures are used:

• hanging;
• layered.

The name of each speaks for itself. Hanging rafters rest only on the outer walls. In the upper and lower parts, they are connected by horizontal tie-beams, which ensure the rigidity of the structure. The rafters in the ridge joint rest on vertical posts, in the middle part - on struts, and the ends are placed on the outer walls.

Structural schemes of hanging and layered truss systems of hip roofs

In addition to the classic hip roof, there are several varieties of it, created for reasons of aesthetic appeal:

• half-hip 4-pitched (Danish);
• gable semi-hip (Dutch);
• tent (4 identical hip slopes);
• hip with a broken slope.

Calculation features

The process of calculating a hip roof can be divided into three stages:

• The choice of the angle of inclination of the slopes, depending on the type of roofing material.
• Determination of the lengths of the structural elements of the roof, based on the drawings of the cross-section of the building and the plan of the floor to be covered.
• Selection of the cross section and pitch of the rafters along their length, taking into account the type of wood used and the normative snow load of the construction region.

The angle of inclination of the slopes depends on the material of the roof. Therefore, when making a diagram of a truss structure, it is necessary to take into account its minimum value recommended by the standards (in degrees):

• for slate - 22;
• soft tiles - 11;
• metal tiles - 14;
• corrugated board - 12;

For a roof made of a waterproof membrane, the angle of inclination of the slopes can be any. Based on the minimum allowable slope value, its actual value is chosen depending on the purpose of the attic space.

If a living space is built under the hip roof, then its slopes should have an angle of inclination that allows comfortable movement within the "living area".

The actual length of the structural elements of the roof is easiest to determine by drawing the truss system in a scale convenient for measurements.

Knowing the length of the rafters, their pitch and cross section can be found in the table. Here the dependence of the geometric dimensions of the rafters on the type of wood and the magnitude of the snow load of the construction region is indicated.

Selection of the section of the rafters and their pitch depending on the length, type of wood and snow load

This table can also be successfully used in reverse order. By choosing the pitch and section of the rafters, the type of wood and the amount of snow load, you can easily find the maximum length of the rafters allowed by the standards.

The cross section of the Mauerlat beam must be no less than the cross section of the rafter leg. Most often it is 10x15 cm, 15x15 cm or 15x20 cm. The cross section of the ridge beam is usually equal to the cross section of the rafter legs.

For the lathing, a board 25 mm thick is used, stuffing it at the interval recommended for the selected roofing. For the installation of a solid flooring on the roof frame, an OSB plate with a thickness of 12-15 mm is used.

Mounting Features

Judgments circulate on the Internet that the installation of a hip roof is very difficult and time-consuming. There is some truth in this, but, in essence, the assembly of this structure is not much different from the construction of a conventional gable roof.

Hip roof for a gazebo - invaluable assembly experience

The process of installing a hip roof truss system includes several stages:

1. A mauerlat is laid along the perimeter of the walls. In this case, it is placed on steel threaded studs embedded in the masonry and tightened with nuts. At the docking sites (at the corners of the house and at the splicing points), landing planes are selected on the Mauerlat, cutting off half of the beam.

2. The further sequence of work depends on the width of the overlapped span (roof area). This point must be taken into account at the stage of drawing up a drawing or a roof diagram.

Racks supporting the ridge beam can be dispensed with if the width of the building (span) is less than 7.5 meters. With a house width of 6 to 7.5 meters, the hanging rafters in the upper part must be connected with a crossbar (a beam with a section of 50x100 mm).

If the width of the building is small (up to 6 meters), then lower puffs (floor beams) will be sufficient to ensure the rigidity of the truss system.

Having laid the Mauerlat, the central axis is marked on the end walls. Two extreme racks are set along it and fastened with temporary struts to the floor beams. If the building is covered with panels, then a central beam is laid along them (the cross section is the same as that of the Mauerlat). The lower ends of the extreme racks are fixed on it.

The initial stage of installation - the installation of vertical racks under the ridge

Intermediate racks are placed in increments of 1-2 meters. If the house is covered with beams, then the racks can be mounted on them, fixing them with brackets or self-tapping screws.

3. A ridge beam is laid on the racks, the places for installing the rafter legs are marked on the Mauerlat and they are mounted. To attach the rafters to the Mauerlat, a notch is used (a cutout is made on the rafter leg for tighter contact).

Cutting the rafter leg into the Mauerlat increases the reliability of the joint

4. Hip (sloping, diagonal) rafters are fixed with the lower end to the Mauerlat, and with the other end to the junction of the ridge beam and the extreme ordinary rafters.

After that, short rafter legs (spiders) are attached to them.

Anyone who wants to make a hip roof with their own hands must remember that the main attention here is paid to the quality of assembly of nodes. It is very responsible to approach the installation of the ridge beam, the joining of the diagonal rafters with the ridge and with the sprigs.

The joint of the sprig with the hip rafter

On large roofs, the standard length of the beam (6 meters) is not enough to make a solid diagonal rafter. Therefore, it is assembled from two parts, securely fixing them together.

The overhangs of the hip roof are made by stuffing on the rafter legs trimmings of a beam or a thick board (filly) that extend beyond the perimeter of the walls by 50-100 cm.

Having finished the installation of the truss system, the crate is nailed to it and the roofing material is laid.

Country plots are not large. Therefore, many build houses of small area and increase living space by creating additional living quarters in the attic. This is possible if the hip roof truss system is correctly installed.

Such a roof is made in the form of four slopes. Two of them are classic lateral ones in the form of a trapezoid, and two more are triangular at the ends of the roof. Unlike a hip roof, where all four slopes converge at one point, a hip roof has two peaks connected by a ridge.

Hip roof with four slopes

It is the side triangular gables, which are performed with a slope, and are called hips. The gable roof also has triangular end gables, but they are located strictly vertically, at the hip roof these slopes are inclined, which is a hallmark of this type of roof.

Double pitched roof

A hip roof is called if the end slopes, starting from the ridge, reach the outer wall, that is, to the eaves. But there are options when the ramp is interrupted and in one place goes into a vertical plane. Then such a roof is called half-hip or Dutch.

According to the method of installation and the use of various materials, such roofs can be classified as complex structures. In general, the design of the hip roof consists of a Mauerlat, a ridge beam, rafters - angular, short and intermediate.

Mauerlat is a wooden beam mounted around the entire perimeter of the house at the very top of the walls. It serves for the correct transfer and distribution of loads exerted by wind, snow cover, the weight of the roof and itself on the load-bearing walls of the building. This element is a connecting upper trim for walls made of piece materials - brick, concrete blocks.

Mauerlat hip roof

For walls made of logs or timber, the Mauerlat is not suitable. Its role is performed by the upper crowns of the log house.

The ridge beam is the main element of the truss system, which connects all the roof slopes into a single structure. It must be of the same section with the rafter legs. Otherwise, in the future, a distortion of the entire truss structure and the roof as a whole may occur.

Corner rafters, otherwise called slanted or diagonal rafters, are the basic power parts that connect the corners of the building box with the ridge beam. For their manufacture, you will need a board equal in thickness to a ridge beam. At one end it is attached to the ridge, the other rests on the Mauerlat. Depending on the roof project, a different number of such rafters is used, but not less than four.

Corner rafters hip roof

Short rafters can be of different lengths, but when assembling the roof structure, they are all displayed at the same angle and are parallel to the intermediate rafters. When the necessary calculation of their number is made, first of all, the area of ​​\u200b\u200bthe entire roof is taken into account. At one end, the short rafter legs are connected to the corner rafter, and at the other they rest on the outer wall of the building.

The central rafters are installed with the upper end on the ridge beam, the lower end rests on the load-bearing walls of the house. As a rule, their calculation is as follows: three on one side of the roof and the same number on the other, but when designing truss systems for large houses, an increase in their number is allowed.

Intermediate rafters are elements that are mounted on a ridge on one side and rest on a Mauerlat on the other. They are usually not used on hip slopes, since the entire area is covered with short rafters. The calculation of the cross section and the number of intermediate elements is based on the bearing capacity of the truss structure and the type of roofing material.

If the building is large, it will be necessary to install additional reinforcing elements in the form of struts and vertical posts supporting the ridge beam, and trussed structures to prevent sagging of the diagonal rafters.

Rafter systems in these types of roofs are made in various versions. For example, if the hip slope does not reach the ridge, as a result of which a vertical small triangular pediment is formed at the top, then such a roof is called Dutch.

Dutch hip roof

Hip roofs also stand out. They have all four slopes of the same shape, and there are simply no side gables in such designs. Hips in this embodiment are triangular surfaces, the slope of which is made at the same angle with other slopes. As a rule, such systems are used for buildings that have a square-shaped area in the projection. In the group of hip roofs there are semi-hip mansard roofs, four-slope, gable, multi-gable and gable.

Hip roof

In addition, there are broken roofs, consisting of slopes of various sizes, the angle of inclination of which is different. Such structures are very complex in design, and it is also difficult to calculate them. Therefore, they are not common, but it should be noted that they have a very attractive appearance. You can evaluate the effectiveness of roofs with a broken structure of the truss system in the video, which also talks about the features of their construction.

The device of hip truss systems begins with the development of their project. A correct and competent project will allow you to assemble the roof in a short time. The optimal choice of the angle of inclination of the slopes is determined depending on the climatic conditions:

• In a region where windy weather prevails, the angle of inclination should be smaller, this will reduce the wind load on the roof.
• During snowier winters, the angle of inclination of the slopes, on the contrary, is increased so that ice and snow do not accumulate on the roof.

Hip truss system project

When choosing the angle of inclination of the rafters, accordingly, the calculation of the required amount of material is also carried out. And if for the lathing in almost all cases the calculation is based on the total area of ​​\u200b\u200bthe roof, then the number and cross section of angular and short rafters are calculated separately, depending on the type of roof chosen.

In addition to the climatic features of the region, when choosing the angle of inclination, the type of roofing material is taken into account:

• If type-setting material is used, for example, slate or metal tiles, then in order not to increase the load on the rafters, it is better to make the angle at least 22 °.
• When using roll coatings, the number of layers is taken into account. The more of them, the less you can make the slope of the slopes.
• The device of a larger angle of inclination of the slopes allows the use of roofing material - corrugated board, but the height of the profile is taken into account. The angle of inclination in this case can vary in the range from 20 to 45 degrees.

The choice of the angle of inclination of the roof according to the material

The correct calculation of the angle of inclination of the roof begins with the determination of the end axis of the building on the upper trim. After that, it is necessary to mark the middle of the ridge beam, at this point the central rafter leg will be located. Then it is necessary to determine the location of the next intermediate rafter, for which the distance corresponding to the calculation of the distribution of intermediate rafter legs is measured. In most cases, it does not exceed 70–90 cm.

The length of the rafters is determined so that their lower end protrudes 40–50 cm above the outer wall, and the upper end rests on the ridge beam.

A similar calculation is carried out on all four sides of the roof to calculate the location of the intermediate rafter legs on the ridge beam. An example of their correct location is shown in the photo.

When designing hip roofs, two types of rafters can be used - hanging and layered. Hanging ones rest only on the walls of the building, transferring all spacer loads to the Mauerlat. If an attic device is planned, then additional installation of metal or wood screeds will be required, which are laid on the load-bearing walls of the building and subsequently serve as the basis for the floor device. The photo shows how mansard hip roofs with a hanging truss system are arranged.

Mansard hip roof with hanging truss system

Laminated rafters are used if they are supported in the form of columns or internal load-bearing walls. When designing the system, alternation of two types of rafters is allowed. Where the inner walls play the role of supports, they are attached to the walls, and in other places they are hanging.

The fastening of the rafters is mainly carried out by means of sawing (saddles). But their depth cannot exceed a quarter of the width of the rafter board. In order for the wash to be the same on all legs, you need to make a template. In addition, the elements of the truss system are attached using metal corners, self-tapping screws, nails. Fastening can also be done with brackets, bolts and studs.

Fastening the elements of the hip roof truss system

When installing the Mauerlat, do not forget to lay a layer of waterproofing along the top of the walls. If the walls are made of brick, then embedded parts are installed in the last rows of masonry for further fastening of the Mauerlat. Such fasteners can be made in the form of vertical studs or bolts, installed in increments of no more than one and a half meters.

Hip roofs are complex structures, but this does not in the least reduce their popularity. Despite the complexity of the construction, they make it possible to arrange additional living quarters in the attic space, and if you carry out high-quality work, you can also operate it in the winter.

The most important element of the house, which affects the entire building, is the roof. Its design is selected, taking into account the weather conditions in your area and the materials that are used in construction. And, of course, the appearance of the roof is of great importance. Among all the structures, the hip roof deserves your attention most of all.

Features and design of the hip roof

The hip roof is especially popular, as it has high strength characteristics, durability and an original look. It is also worth noting its extraordinary configuration. The hip roof will be an excellent choice when arranging a residential attic floor, as it allows you to simplify the procedure for creating skylights.

In addition, the hip roof has a streamlined shape. And thanks to this, it is not as much subject to destruction from wind loads as other structures. The ridge of the roof, in turn, is not undermined by gusts of wind. And you should pay attention to this property if you live in southern regions with strong winds.

The hip roof is represented by four slopes. They slope on all sides of the building. Two slopes are lateral, like a classic roof structure. Two more, additional, are located between the two previous ones. In the hip roof, unlike the hipped variety, there is not one peak, but two. They are interconnected by a ridge.

Vertical gables look like inclined triangular slopes. They are called hips. It turns out that two slopes in a similar design take the form of a trapezoid - along the long sides. And on the butt - a triangular shape.

The design of the hip roof consists of the following key elements:

• Skate beam. It is this element that is the top point of the roof and its main bearing axis. In this place, all the faces are also connected. Most often, when erecting a hip roof, the center of the ridge coincides with the center of the entire roofing.
• Corner rafters. Rafter legs of the sloping type act as basic strength elements and connect the ridge beam and the corners of the building. For their cutting, boards are used, the thickness of which is equal to the thickness of the ridge. The rafter leg is attached to the ridge at one end, and the other end goes beyond the boundaries of the house. You will need four pieces, depending on the project.
• Short rafters. They may be different in length, but come out at the same angle. When determining their number, the area of ​​\u200b\u200bthe roof is taken into account. Short rafters are connected at one end with angular rafter legs. And for others, they rely on the Mauerlat or the corner of the building, they are not attached to the ridge.
• Ordinary frame. The central intermediate rafters are installed at the ends of the ridge beam and are displayed on the load-bearing walls of the building. Their number is six, three on each side.
• intermediate frame. Intermediate rafters start on the ridge, and the other side rests on the Mauerlat. They are not installed on the hips.

Varieties of hip roofs

Before installing a hip roof, you should figure out what they are. If the construction with a hip breaks off above the level of the side slopes, then the roof is called Dutch. Also sometimes you can find the name Danish roof. This design is more difficult to build than the classic hip. However, old houses with a similar roof for decades, and sometimes much longer, stand unchanged.

There are also hipped hip roofs, the slopes of which take the same shape. There are simply no side slopes. The hips form the same angle. Hipped roofs are equipped exclusively for square-shaped houses.

You can also find various unusual broken variations of the hip roof. The design consists of slopes that are of different sizes and diverge at different angles. Complex broken hip roofs are rare, but they have the most spectacular appearance.

Do-it-yourself hip roof

The device of the hip roof should begin with the design of such a structure. If you develop the scheme correctly, then it will be possible to assemble it yourself without involving additional workers.

Roof slope

The optimal angle of inclination of the roof should be determined depending on the climatic conditions in the region:

1. The slope in windy areas should be as small as possible. So you can protect yourself from heavy loads on external walls.
2. The slope of the roof for regions where heavy snowfalls occur should be increased. So the snow will quickly melt off the roof.
3. In areas where dry and hot weather prevails, the slope should be kept as low as possible. To forget about overheating forever, choose this indicator at the level of 2-5 °.

• When using stacking material in pieces, for example, slate, create a roof at a minimum angle of - 22 °.
• For a hip roof made of rolled material, the angle of inclination will depend on the number of layers. If you plan to lay two layers, then the angle should be up to 15 °. If you will lay 3 layers, then make an angle of 2 to 5 °.
• When installing a roof from a corrugated board, build a roof at a minimum slope - subject to tight joints from 12 °.
• If you decide to lay a metal tile, make a minimum slope of 14 °.
• For soft tiles, limit the slope of the hip roof to 11 °.
• When the roof is covered with ondulin, the angle reaches 6 °.
• If you have chosen a membrane roof, then remember that it is suitable for roofs that have any slope.

In addition, it is recommended to proportionally increase the slope of the hip roof if the total area and the amount of materials used during work have increased. Therefore, if you are interested in savings, you should take this point into account when designing a hip roof.

hip roof area

Please note that some factors are not included in the calculation of the hip roof:

• dimensions of the chimney;
• dimensions of skylights;
• folds;
• overhangs and parapets not related to roofing;
• slope length,
• elements of bars that protrude above the roofing;
• adjoining.

The roof area is determined in square meters. To carry out such calculations, you can use a special calculator that is easy to find on the net. With its help, the area of ​​\u200b\u200bthe hip roof and the amount of building materials are determined.

To calculate the hip roof, you will have to remember the knowledge gained in geometry lessons. Since the hip roof has two vertices, its total area consists of the sum of the areas of the two side planes (trapezium) and the areas of the two hips (triangles):

1. The hip area can be determined using the formula of an ordinary isosceles triangle: S \u003d 0.5 * a * h, where a is the base of the hip, h is the height of the hip plane.
2. The area of ​​the lateral plane is determined by the trapezoid formula: S \u003d h * (a + b) / 2, where a is the length, b is the base, h is the height. The area of ​​a trapezoid can be divided into the area of ​​one rectangle and two triangles.
3. In this case, the area is recommended to be calculated along the length of the cornices, and not along the edges of the house. If you plan to lay metal tiles or roofing in rolls, then reduce the length of the slope by 700 millimeters.
4. The carpet area can be much larger than the roof itself. This is due to the fact that the materials are stacked with an overlap. Also on the roof there are many additional elements and connections. Therefore, to calculate the amount of roofing material, add 10% to the roof area. If you plan to build a complex roof, then - 15-20%.

Calculation of the truss system

The calculation of the hip roof truss system is a very important job. The rafters must withstand the roofing material, the loads created by wind and snow. Therefore, when calculating, take into account the weight of the materials used to create the roofing and finishing, the weight of the rafter system and the climatic conditions in your area.

For this work, prepare a measuring rail and apply all the markings on it. So you get rid of inaccuracies in measurements. For the manufacture of rails, use plywood, which has a width of 5 centimeters. Also prepare a table showing the ratios of the length and placement of the rafter legs in order to achieve high accuracy in measurements.

Carry out the calculations in the following order:

• The length of the rafter leg is equal to the product of the corresponding coefficient.
• Mark the axis from the end of the building. Do on the top strapping.
• Calculate half the width of the skate. So you find out the location of the first element of the rafter system.
• Attach the end of the rail to the marked line. Another - place along the line of the side wall. Here there will be a place for an intermediate rafter leg.
• To find out the length of the rafter, install one end of the beam on the roof overhang, and place the other on the outer corner of the load-bearing wall.
• Where to place the next central rafter is calculated as follows. Transfer the measuring rail to the edge of the side wall, leave marks on it for the future rafter system.
• Similar actions must be carried out at the three corners that remain. This is how the placement of the ridge and the ends of the intermediate rafter legs is calculated.

To calculate the angle of inclination of a four-pitched hip roof, perform the manipulations in the following sequence:

1. Measure the ground plan of the intermediate rafter leg using a measuring stick.
2. Find the appropriate roof angle in the table. Do the product of these exponents.
3. Measure the length of the rafter from the place where the support is attached to the ridge.
4. Determine the length of the overhang in the same way. Make the product of the corresponding coefficient by the horizontal projection.

Now let's talk about the beveled part. Calculate the rafter leg as follows:

• Measure its length from the corner of the apartment building.
• The projection can be obtained if you produce the squares of the projections of an ordinary frame.
• Multiply the result by the correction. This will be the length of the corner rafter leg.

Installation of supports for rafters

First of all, install supports to support the ridge beam:

1. The lower supports differ, depending on the material used to build the house. In block-beamed or log houses, these functions are performed by the upper crowns of the log house. In buildings that are built using frame technology, the upper frame frame acts as a support. In brick houses, sloping rafter legs rest on the Mauerlat.
2. Mauerlat is needed to distribute the load on external walls. To make it, take a beam of wood, which has a section of 100x100 mm. This element can be laid closer to the inner edge of the wall or in the center.
3. To prevent the roof from being blown off by the wind, attach it with wire twists. Keep a step of 1000 mm while doing this.
4. So that you can freely inspect the Mauerlat and rafters, maintain certain distances. From the attic floor to the Mauerlat should be at least 400 mm.
5. The upper support for the system of slanting and diagonal rafter legs is a beam, the cross section of which is equal to the cross section of the diagonal rafters.
6. In the design of the hip roof there are no brick gables that a gable roof has. Therefore, install racks under the ridge beam, which have a section of 100x100 mm. They are arranged in increments of 3-4 m, as shown in the photo of the hip roof.
7. Rest the rack on the bed. Lay it on an interior load-bearing wall or floor slab. In the first case, a board is used to make the bed, which has a section of 50x150 mm. In the second situation - a bar that has a section of 150x150 mm. Be sure to lay rolled waterproofing under the bed.

Installation of the truss system

When installing a system of sloping and diagonal rafter legs of a hip roof, follow these instructions:

• The rafters are attached to the inner corners of the walls, and the diagonal rafters are attached to the outer ones. The length of the first is longer than conventional rafters, since they are assigned one and a half times a large load.
• The shortened rafters of the slopes will rest on the rafter legs of the oblique type. They are called rogues. They are usually made paired from two ordinary legs.
• Supports are installed under the diagonal rafters - one or two. For their manufacture, use racks of timber. The struts are placed at an acute angle of 45°.
• The intermediate rafter legs rest on top of the ridge beam, and on the bottom - on the Mauerlat. When installing them, adhere to a step of 1.0-1.2 m. The sections of such legs must be chosen, depending on the beam layout - one- or two-span, the pitch of the rafters created by the weight of the roof and the snow load. Remember that intermediate rafter legs should not be too long.
• Fasten every second rafter to the supporting wall with twists. Make them from 2 wires that have a diameter of 4 mm. Connect the intermediate frame to the Mauerlat. Use a back brace for this.
• Angled rafter legs are known as sprigs. They are also often called half-legs, as they have a shortened length. On the one hand, the sparrows rely on the Mauerlat, on the other, on the diagonal leg. To evenly distribute the load from the corner legs to the slanted sprigs, they are attached to the diagonal ones in different places, according to the scheme of the hip roof.
• For symmetrical placement of all rafter legs, make marks on the ridge beam and Mauerlat. The most important point in the manufacture of the hip roof rafter system is the competent connection of all elements in places where the central and diagonal rafters intersect. To do this, make cuts on the bars that have a double bevel.

Roof reinforcement and framing

In order for the design of the hip roof to be durable and reliable, it is not enough just to make a strong truss system. It also needs to be reinforced.

1. For reinforcement, a sprengel is placed in the corners - a beam that is thrown between the shoulders of the Mauerlat and forms an angle. These racks are designed to support the diagonal rafter legs. If the sprengel is located far from the corner, then it is recommended to attach a farm to it.
2. Install racks on the ceiling, which are connected from above with a beam. It acts as a real support for the rafters and ensures an even distribution of the load on the building. Such racks serve as shelves.
3. If the diagonal rafters are very long, then you should use twin beams instead of a single beam, as shown in the hip roof video.
4. To create the crate, it is recommended to use wooden boards. Also, bars with a section of 40 by 40 or 50 by 50 mm are suitable for this purpose.
5. Pre-treat the wood with a protective compound, then dry thoroughly. It is better not to take raw boards for work, as they can cause deformation of the roofing.
6. The crate is placed perpendicular to the rafter legs. Rafters should be placed in a continuous layer. You can also install them in increments of 10-15 cm. The method of arranging the sheathing depends on the type of roofing material. For example, for a soft roof, the crate is only allowed to be solid.

Roofing pie device

After installing the crates on the hip roof, you can start arranging the roofing pie:

• First, lay a layer of waterproofing material to prevent water from getting under the roofing. Also, waterproofing will help to avoid the formation of condensate. Fix it to the rafters using a construction stapler. From above, reinforce with a counter-lattice, not forgetting about the gaps between the roofing and waterproofing material to create ventilation.
• The placement of vapor barrier and thermal insulation material will depend on the purpose of the attic. Decide whether it will be warm or cold. In a cold attic situation, insulate the floor because heat leakage from the living space is minimal. In the case of a warm attic, insulate the roof as well. Lay the insulation between the rafters. Then sheathe the back surface of the hip roof with construction paper. As a result, you will get a ceiling for the attic.
• Vapor barrier material is often placed under the insulation. It is placed on top. Therefore, you should count on a large consumption of material.
• When choosing a roofing material, consider its appearance, strength characteristics, reliability and durability. Also pay attention to the weather conditions in the region and the angle of your roof.
• The hip roof is a classic design, so clay tiles that do not deform and do not fade will look great.
• Take a closer look at other tile materials - bituminous and metal tiles. They have a budgetary cost, are distinguished by simple installation, are characterized by high rates of resistance to various kinds of damage and sound insulation.
• It is allowed to use sheet variants of roofing material from a metal profile. To achieve the most original hip roof look, consider copper cladding. This is an expensive material that increases the price of a hip roof. However, its cost is more than justified by environmental cleanliness and great endurance.
• Then take care of covering the ridges and cornice overhangs, finishing the chimney pipes in those places where they pass through the roof, arranging grooves and dormer windows. Pay special attention to the installation of snow retention elements, gutter systems and roof railings.

Thus, hip roofs are very popular. Especially if you decide to build a small country house or cottage. Take a closer look at the hip roof when building an office building of a representative nature. In addition, such a design would be ideal for building original architecture with elevations, ledges and turrets. And also the hip roof is ideal for the construction of the attic floor.

Hip roofs have many advantages. They are beautiful, reliable in all weather conditions, the four-sided design allows you to effectively insulate the house from the side of the roof. Some difficulty is the device of the truss system. We will deal with its schemes and calculations in this article.

Hip roofs, sometimes called Dutch and Danish, are distinguished by good quality, reliability and spectacular European design. The truss base of such roofs consists of many basic and reinforcing elements that require drawings or three-dimensional drawings, accurate calculations and execution.

Hip roof varieties

Hip roofs, in addition to the basic classical design, consisting of two trapezoidal slopes and two triangular end hips, also include their varieties:

1. Half hip double slope.
2. Semi-hip four-slope.
3. Shatrovaya.
4. Hip-pediment.

Each variety has its own scheme of the truss system. Next, we consider and calculate the classic hip roof.

Scheme and main elements

To perform the calculation of the truss system, you need to familiarize yourself with its basic scheme, the main and auxiliary elements.

The main elements of the truss system

The main elements include (see the figure below):

1. Mauerlat. It is a beam fixed along the perimeter of the outer walls, indented from the outer edge. Attaches to the wall. Mauerlat disperses the load from the pressure of the rafters, connects the truss system with the walls of the house, and is the basis of the roof.
2. Skate. Upper crossbar for fastening the rafters of the roof slopes. The height of the ridge depends on the angle of inclination of the slopes. Gives the system rigidity and strength.
3. The central rafters of the slopes. The ends of the ridge are supported on the sides of the Mauerlat. There are 4 such elements in the system. - 2 pcs. on every slope.
4. The central rafters of the hips. The ends of the ridge are supported on the end sides of the Mauerlat. There are 2 such elements in the system. - 1 pc. on every hip.
5. Skew legs (diagonal, corner rafters). Connect the corners of the Mauerlat with the ends of the ridge. They are part of the supporting structure. There are 4 of them in the rafter system.
6. Intermediate rafters of slopes. They are installed parallel to the central rafters of the slope between them with the same pitch, relying on the side of the Mauerlat and the ridge beam. If the length of the ridge is insignificant, they may not be used.
7. Shortened rafters of slopes. They are installed parallel to the central rafters of the slopes and have a variable length - the closer to the corner, the shorter. They rely on the side of the Mauerlat and slanting legs. The number of elements depends on the installation step.
8. Shortened hip rafters or sprigs. They are installed parallel to the central rafters of the hips and have a variable length - the closer to the corner, the shorter. They rely on the end part of the Mauerlat and oblique legs. The number of elements depends on the installation step.

Scheme and main elements of the truss system

You can read more about attaching rafters to the Mauerlat in our article.

The above elements are basic, basic. Other elements are designed to reinforce the main ones and are used in critical buildings, for example, for residential buildings:

1. Vertical racks for supporting the ridge beam. They rely on crossbars (see below), laid parallel to the end of the house or a bed located along the longitudinal axis of the building (if there is a main wall under it).
2. Crossbars or puffs. The rafter legs of the slopes are connected in pairs. They serve as a support for racks and diagonal struts (see below). They can serve as floor beams if they are built into the Mauerlat or installed directly into the longitudinal walls of the house. If the puffs are placed closer to the ridge, they will become the basis of the attic ceiling.
3. Diagonal braces (braces). They are used to increase the rigidity of the system if the length of the rafters is more than 4.5 m. The use of struts allows you to reduce the cross section of the rafters, which they reinforce.
4. Sprengel. Beam installed in the corners of the Mauerlat. Serves for mounting a stand that supports and reinforces the oblique leg.
5. Wind beam. It serves to resist the deformation of the rafter legs in gusty, strong winds. It is attached to the rafters of the slopes from the inside, obliquely, on one or both sides - it depends on the wind load in the construction area.
6. filly. An element of a smaller section than the rafters themselves. Extends the leg of the rafters to provide a roof overhang when a single piece is not available due to limited lumber length or for cost reasons.

Gain elements

Calculation of the truss system

The calculation of the system includes the choice of the angle of inclination of the slopes and hips and the calculation of the lengths of its main and auxiliary elements.

The choice of the angle of inclination of the longitudinal and end slopes

The choice of the angle of the slopes and hips ranges from 25-45 ° and depends on the desire to have an attic, the roofing material adopted, the assessment of static (roof weight) and dynamic (wind, snow) loads.

In hipped roofs, the angle of inclination of the hips and slopes is the same. In hip roofs, the same angles are also often taken in terms of aesthetics, but they may differ if this is the architect's idea.

Recommendations for the use of roofing materials

For a better understanding of the calculation algorithm, consider as an example a hip roof of a house with sides of 8 and 12 m, and a ridge height of 2.5 m. Let's take the angle of inclination of the slopes at 35 °, and the angle of inclination of the hips - 45 °.

Calculation of the main truss elements

The classic hip roof consists of two slopes in the form of trapezoids connected in a ridge, and two hips - end slopes in the form of triangles.

First you need to remember some formulas from the school algebra curriculum. This is the ratio of the lengths of the sides of a right triangle, expressed in terms of the trigonometric function of the angle and the Pythagorean theorem.

Trigonometric functions of an acute angle of a right triangle

Let's depict the frame of the truss system in an axonometric view:

Let's calculate the main elements of the truss system.

1. Calculate the length of the central hip rafter CD, which is the height of an isosceles triangle (hip) and the hypotenuse of a right triangle whose height is equal to the height of the ridge (CE = 2.5 m). Angle of inclination of the hip α = 45°. Sin 45° = 0.71 (according to the Bradis table).

According to the trigonometric relation:

• CD = CE / sin α = 2.5 / 0.71 = 3.52 m

2. Determine the length of the skate K. To do this, from the previous triangle we find the length of the base ED, using the Pythagorean theorem:

House length: BL = 12 m.

Skate length:

• CF \u003d 12 - 2.478 x 2 \u003d 7.044 m

3. The length of the corner rafters CA can also be obtained from the Pythagorean theorem for triangle ACD. Half the width of the house AD = 8 / 2 = 4 m, CD = 3.52 m:

4. The length of the central rafters of the slope GF is the hypotenuse of the triangle, the legs of which are the height of the ridge H (CE) and half the width of the house AD:

The intermediate rafters of the slopes have the same length. Their number depends on the pitch and section of the beams and is determined by calculating the total load, including weather.

These tables correspond to the atmospheric loads of the Moscow region

Let's compare the maximum, average and minimum section of a beam with a length of 4.717 m (see the values ​​​​for 5.0 m).

At section 100x250 mm the step will be 215 cm. With a ridge length of 7.044 m, the number of intermediate rafters will be: 7.044 / 2.15 = 3.28 segments. We round up - up to 4. The number of intermediate rafters of one slope - 3 pcs.

• 0.1 0.25 4.717 3 2 = 0.708 m 3

At section 75x200 mm the step will be 140 cm. With a ridge length of 7.044 m, the number of intermediate rafters will be: 7.044 / 1.4 = 5.03 segments. The number of intermediate rafters of one slope - 4 pcs.

The volume of lumber for both slopes:

• 0.075 0.2 4.717 4 2 = 0.566 m 3

At section 50x175 mm the step will be 60 cm. With a ridge length of 7.044 m, the number of intermediate rafters will be: 7.044 / 0.6 = 11.74 segments. We round up - up to 12. The number of intermediate rafters of one slope - 11 pcs.

The volume of lumber for both slopes:

• 0.05 0.175 4.717 11 2 = 0.908 m 3

Therefore, for our geometry, the optimal option from the point of view of economics would be a section of 75x200 mm with a step of 1.4 m.

5. To calculate the lengths of the shortened slope rafters MN, you again have to remember the school curriculum, namely the triangle similarity rule.

Similar triangles on three sides

The large triangle that we need to reinforce with shortened rafters has known dimensions: GF = 4.717 m, ED = 2.478 m.

If the shortened rafters are installed with the same step as the intermediate ones, their number will be 1 in each corner:

• 2.478 m / 1.4 m = 1.77 pcs.

That is, two segments are formed with one shortened rafter in the middle. A small triangle will have a leg, 2 times smaller than ED:

• BN = 2.478 / 2 = 1.239 m

We compose the proportion of similar triangles:

Based on this ratio:

At this height, the cross section of the rafters is taken according to the table - 75x125 mm. The total number of shortened rafters of both slopes is 4 pcs.

6. Determining the length of shortened hip rafters (spreaders) is also performed from the ratio of similar triangles. Since the length of the central hip rafters CD = 3.52 m, the step between the shortened rafters may be greater. With AD \u003d 4 m, shortened rafters with a step of 2 m will be one on each side of the central hip rafter:

• (2 3.52) / 4 = 1.76 m

With such a height, we take the rafter section 75x125 mm. The total number of shortened rafters of both hips is 4 pcs.

Attention! In our calculations, we did not take into account the overhang.

Calculation of the roofing area

This calculation comes down to determining the areas of a trapezoid (slope) and a triangle (hip).

Let's do the calculation for our example.

1. The area of ​​one hip with CD = 3.52 m and AB = 8.0 m, taking into account the overhang of 0.5 m:

• S \u003d ((3.52 + 0.5) (8 + 2 0.5)) / 2 \u003d 18.09 m 2

2. The area of ​​one slope at BL = 12 m, CF = 7.044 m, ED = 2.478 m, taking into account overhangs:

• S \u003d (2.478 + 0.5) ((12.0 + 2 0.5) + 7.044) / 2 \u003d 29.85 m 2

Total roofing area:

• S Σ \u003d (18.09 + 29.85) 2 \u003d 95.88 m 2

Advice! When buying material, consider cutting and inevitable losses. The material produced by large area elements is not the best option for hip roofs.